The AVL9 Knockout HT-29 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population targeting the human AVL9 gene in the HT-29 colorectal adenocarcinoma epithelial cell line (Homo sapiens). This product comprises a mixed pool of HT-29 cells collectively harboring CRISPR/Cas9-mediated disruptions in the AVL9 locus, providing a versatile loss-of-function model for studying endolysosomal trafficking and autophagy without selection for monoclonal genotypes. The polyclonal format captures a range of editing events, enabling robust assessment of AVL9-dependent phenotypes in a heterogeneous cell context reflective of tumor cell populations.
The HT-29 host cell line is a well-characterized model derived from a female colorectal adenocarcinoma, exhibiting epithelial morphology and carrying a BRAF V600E oncogenic mutation. Widely employed in cancer biology and intestinal barrier function studies, HT-29 cells are particularly suited for investigating colorectal tumorigenesis, metastasis, and therapeutic responses. Their endogenous signaling landscape, including constitutive MAPK pathway activation, provides a relevant background to examine how autophagy intersects with oncogenic drivers.
AVL9 encodes the ??5 subunit of the adaptor protein 5 (AP-5) complex, which mediates retrograde vesicle trafficking from late endosomes to the trans-Golgi network, a process essential for lysosomal homeostasis and autophagic clearance. The AP-5 complex, comprising AVL9 (AP5M1) along with AP5Z1, AP5B1, and AP5S1, interacts with the SPG11/spatacsin and SPG15/spastizin proteins to regulate endolysosomal sorting. Upstream, AVL9 function is influenced by starvation signals, mTOR inactivation, and TFEB-mediated transcriptional programs. Downstream, intact AVL9 activity ensures proper lysosomal degradation, as evidenced by the turnover of autophagic substrates such as p62/SQSTM1 and the processing of LC3-I to autophagosome-associated LC3-II. Immunofluorescence studies demonstrate that AVL9 loss leads to aberrant localization of LAMP2, reflecting disrupted lysosomal membrane dynamics. In the context of autophagy, AVL9 dysfunction results in impaired autophagic flux, with accumulation of p62/SQSTM1 and altered lysosomal pH, underscoring its role as a gatekeeper of cellular degradative capacity.
This knockout model holds particular significance for dissecting the role of endolysosomal trafficking in colorectal adenocarcinoma. HT-29 cells depend on autophagy for survival under nutrient stress and for adaptation to microenvironmental challenges. AVL9 disruption in this background may recapitulate key aspects of hereditary spastic paraplegia type SPG48, where AVL9 mutations lead to neurodegeneration, while simultaneously revealing cancer-specific vulnerabilities. The model enables investigation of how autophagy modulation influences tumor cell proliferation, migration, and sensitivity to lysosomotropic agents such as chloroquine. By comparing wild-type and polyclonal knockout populations, researchers can correlate AVL9 dosage with functional outcomes, including alterations in signaling that bridge metabolism and oncogenesis.
Detailed research applications include monitoring autophagy markers via western blotting (e.g., LC3 conversion, p62/SQSTM1 accumulation) and immunofluorescence (e.g., LAMP2 and AVL9 subcellular distribution), co-immunoprecipitation to assess AP-5 complex integrity, RT-qPCR profiling of autophagy and lysosomal genes, flow cytometric measurement of lysosomal pH, and autophagic flux assays employing bafilomycin A1. Additionally, migration/invasion assays and drug sensitivity tests with chloroquine leverage the HT-29 background to explore therapeutic implications. This AVL9 polyclonal knockout cell pool is a valuable resource for elucidating autophagy-related pathologies in colorectal cancer and for modeling SPG48 disease mechanisms. For further technical details or bulk orders, please contact Ascent Research.
